Watch Cold in July Online Writer-director Jim Mickle's adaptation of Joe R. Lansdale's pulp novel is a genre picture that can't settle on a genre — which is what makes it so entertaining. "Cold In July" starts out as a suspense picture, with Michael C. Hall playing a small-town Texan named Richard who shoots and kills a home invader and then waits nervously for the burglar's ex-con father (played by Sam Shepard) to retaliate.

Watch Cold in July Online Then the movie becomes a mystery, when the local police force resolves the case in a way that Richard finds unsatisfactory. Finally, "Cold In July" becomes a bloody action film, when Richard teams with a colorful private eye (Don Johnson) to confront the Dixie Mafia. Not every part works — nor does it all fit together in a way that has much larger meaning — but it's a gripper from start to finish, because of Mickle's lean style, and because it's impossible to know in the first five minutes where the movie will end up.

To get inside the skin of Richard Dane, an East Texas frame-shop owner who unleashes a torrent of violence by killing a home intruder in “Cold in July,” opening on Friday, Jim Mickle plotted murder. His target was the groundhog that was consuming his upstate New York vegetable garden like so much salad. “I was about to make a movie about a guy who shoots somebody, and I’d never fired a gun, never lived with a gun in my house,” Mr. Mickle said. “It was like character research.”

Armed with a .22 rifle, he lay in wait and — watching the critter devour his plants as if in a scene out of “Caddyshack” — killed it, weeping after he pulled the trigger. “It was the worst experience of my life,” Mr. Mickle said. “It haunts me to this day.” Not exactly the wobbly-kneed admission you’d expect from a director whose “Stake Land,” a zombie-apocalypse western, and “We Are What We Are,” about a family of cannibals, are veritable gore fests.

In “Cold in July” — starring Michael C. Hall as Dane, Sam Shepard as his victim’s vengeful father and Don Johnson as a pig-farming private eye — Mr. Mickle, 34, uses blood to punctuate psychological horrors in a film with a literary heart and more mainstream allure. Recently, Mr. Mickle, his blue eyes glinting beneath devilish brows as he fidgeted in his chair, spoke with Kathryn Shattuck about the machinations behind the macabre. Here are excerpts from the conversation.